Modem communication networks are composed of many nodes that are interconnected to facilitate communication and provide redundancy. These nodes may be interconnected via cables, twisted pair, shared media or similar transmission media. Each node may include, for example, communication devices, interfaces, and addresses. The topology that describes how the nodes of a communication network are interconnected can be complicated. When there is a failure within the communication network, a network manager needs to accurately determine where the failure occurred and the severity of the failure without generating too much superfluous information about nodes impacted by the failure. One approach to determine the location of a network failure involves analysis of the route information that is available to a network manager. In a simple network without redundancy, path analysis may be used to locate a network failure. However, when the network has many nodes and uses fault tolerant redundancy, the route information may not correctly identify the node that caused the failure.
Modem networks include redundancy in the data link and routing layers. Even so, when a core device fails in the network it can cause different parts of the network to be disconnected from a network management station. It is the responsibility of the network management system poller and analyzer to find these faults and determine the root cause without burdening the operator with superfluous information about impacted devices. The redundancy in the network connections and failover protocols utilized by devices make it difficult for the management station's poller/analyzer to determine the current route from a management station to a specific device. This problem is compounded in a duplicate IP network where Network Translation Devices are utilized. As a result, failure analysis techniques using path information are unreliable for modern networks.